Molecular genetic characteristics of Duchenne-Becker muscular dystrophy in the Republic of Moldova

Solution to some problems of clinical genealogical and molecular genetic study of Duchenne muscular dystrophy (DMD) in the Republic of Moldova and prenatal diagnosis aimed at preventing the birth of infants with this disease is proposed. An integrated clinical and molecular genetic study of families with a high risk of DMD has allowed its specific characteristics in the Moldovan population to be identified. The spectrum of mutations at the gene level in DMD patients and their role in prenatal and clinical diagnosis has been determined. RFLP analysis and PCR have been used to estimate the informativeness of families with a high DMD risk; prenatal diagnosis has been performed in some of them. Population analysis of the frequencies of polymorphic restriction sites have been carried out for loci pERT87-8/Tag1, pERT87-15/BamH1, and 16intron/Tag1. The results of analysis of deletion frequencies in the dystrophin gene and the frequencies of the pERT87-8, pERT87-15, and 16intron intragenic polymorphic loci have served as a basis for a strategy of molecular diagnosis. The new strategy allows the informativeness to be evaluated and, hence, clinical, preclinical, and prenatal diagnosis to be performed in approximately 94% of cases. A modified PCR method (MPCR) using the system of primers pERT87-8/Tag1 and 16intron/Tag1 has been developed for direct search for deletions. The method makes it possible to avoid diagnostic errors and decrease both the duration and the cost of the analysis.